how to repair this rusted hole in a post?

[wozzzzza]

got this hole in a post frame that is rusted though, still nice and solid just this rust hole, how would you do this?? i know of a few ways just want probably a better way.

[droog]

got this hole in a post frame that is rusted though, still nice and solid just this rust hole, how would you do this?? i know of a few ways just want probably a better way.

As per any rusted metal repair, cut out the rust and weld new same thickness material in its place. Make sure you pre coat anything that will not accessible after welding.
Depending on whats outside of view in the picture possibly replace top of entire post.

[wozzzzza]

As per any rusted metal repair, cut out the rust and weld new same thickness material in its place. Make sure you pre coat anything that will not accessible after welding.
Depending on whats outside of view in the picture possibly replace top of entire post.

yeah i guess i can try welding, replace post not an option as about 500kg, around 6mm thick and huge and concreted in ground

[ErrolFlynn]

I can't help thinking that the post is full (or partially full) of water. It may continue to rust following your repair.

Consider replacing the post, or adding a drain hole at the bottom, or even pouring some rust inhibitor into the post before sealing it. At least that will prevent the water that is inside from behaving like water.

[droog]

yeah i guess i can try welding, replace post not an option as about 500kg, around 6mm thick and huge and concreted in ground

6mm that puts a different perspective on it. I was thinking 2-2.5mm, surrounding areas do not look that bad.
Check the inside to see if it is rusting from the inside out.

[wozzzzza]

I can't help thinking that the post is full (or partially full) of water. It may continue to rust following your repair.

Consider replacing the post, or adding a drain hole at the bottom, or even pouring some rust inhibitor into the post before sealing it. At least that will prevent the water that is inside from behaving like water.

its got a drain hole at the bottom already and i have thought of spraying it internally somehow, any ideas on that??

[ErrolFlynn]

As you already have a large hole at the top, one of those cameras that plumbers use would give you some idea. The trouble is, rust tends to be flaky and an inspection like that might not tell you a lot. You won't be able to chip at it from the inside. But if the camera view shows the inside to look like a brand new length of steel you are probably going to be okay.

Just to contemplate an idea: There are gadgets available to detect body filler in cars. I've only seen the ones that use a magnet and spring. There are others available. The idea was that if the actual metal was further away (covered in body filler) there would be a weaker reaction to the magnet than if there was just paint covering the steel. Perhaps the same device can also indicate the thickness of the steel. I'm assuming there might be a greater effect with thick steel (ie. no rust) as there would be with a thin wall thickness (lots of rust). I've never done this so I have no idea whether it would work or not.

You could always drill a few small holes in the post. Drill in stages. Watch the depth as you go and take notes. If you go all the way through, put a spot of weld on them afterwards.

I've heard welders say that you must have drain holes to allow condensation to escape, and so minimise rust. But that's not a good argument because, on the other hand, if you enclose the tube properly (ie. air-tight), water will not enter, and rust will not take place.

[droog]

If you want to confirm the thickness of the steel there are ultrasonic testers intended for the purpose that are non intrusive.
They are regularly used to confirm roll cage member wall thickness for certifying automotive racing safety classification.

[ErrolFlynn]

I doubt Wazza has anything like that in his tool kit.

[droog]

I doubt Wazza has anything like that in his tool kit.

Totally agree that its probably not in his toolkit. Also doubt that he has one of the gadgets you were referring to in his toolkit also.
That does not mean there is no way one could not be used to check the wall thickness.

https://www.kennards.com.au/for-hire...hickness-gauge

[ErrolFlynn]

I wish these hire places would put prices on their websites. Never been impressed by their prices.

kennards.JPG

A quick web search.

Capture.JPG

[wozzzzza]

na dont have one of them, i got verniers but useless for that. $169 from kennards. will see what give, i will put my small camera down it see what it looks like. probably 40 years old.
rust patch started as it had a slim light box under that covering it up and i guess it was rubbing and holding a bit of water at that point, didnt even know it was rusted until i took that lightbox off.

[havabeer69]

depends on how structural you really need it.

if its just for looks you can:

wire wheel the rusty part
get spray foam can
fill void with spray foam
use a knife, chisel to cut the excess foam off
carve the foam slightly so its concave into the hollow section of steel
buy some 5min steel putty or use two part builders bog
fill the concave bit with bog
sand smooth
paint
don't point it out to anyone

[wozzzzza]

just for looks really.

[droog]

just for looks really.

Is it really a 6mm wall RHS for a decorative post ?
Not supporting anything ?

If it is just decorative then one of the epoxy putties after cleaning back to bare steel may be a lot simpler than welding.